GlasgowRob 0 Posted May 30, 2006 what voltage should my injectors show when cranking??? oh and what would stop the car sending any voltage to the injectors (although got a good spark and fuel pumps running Share this post Link to post Share on other sites
Pug_101 0 Posted May 30, 2006 what voltage should my injectors show when cranking???oh and what would stop the car sending any voltage to the injectors (although got a good spark and fuel pumps running I can't say for certain on Peugeots, but most injectors run at 5Volts, but it may not show up on a cheap multimeter as it happens so fast. You should really use a Oscilloscope to watch the injectors working. It would show a square wave pattern if it's OK. If you've got no CPS (crank sensor) input into your ecu it may not fire the injectors. Just my 2c worth, hope it helps. Cheers Share this post Link to post Share on other sites
GlasgowRob 0 Posted May 30, 2006 I can't say for certain on Peugeots, but most injectors run at 5Volts, but it may not show up on a cheap multimeter as it happens so fast. You should really use a Oscilloscope to watch the injectors working. It would show a square wave pattern if it's OK.If you've got no CPS (crank sensor) input into your ecu it may not fire the injectors. Just my 2c worth, hope it helps. Cheers quick Q did all 205 gti's have a crank position sensor? Share this post Link to post Share on other sites
Pugnut 9 1 Cars Posted May 31, 2006 The injectors are 12v on these . the polarity is opposite as what you'de imagine . the +12v is fed from the tachometric relay and the -12v is switched(pulses) from the ecu. so while cranking you should see +12v that doesn't pulse at all between one of the injector pins to the BATTERY earth if you're multimeter has a frequency input (Hz) you can connect to the battery + and the switching - on the injector plug and you should register a frequency (set to Hz while on the Vdc setting) or go between the switching - on the injector plug and the battery -12v(set to Hz while on the Ohms setting) it all depends on the multimeter , 99% of fluke and possibly avo multimeters have this ability but others i cant speak for. oh and what would stop the car sending any voltage to the injectors (although got a good spark and fuel pumps running the tach relay , next to you're ecu or a dodgy signal wire back from you ignition amp to the ecu/tach relay? (assuming you have a standard 8v?) Share this post Link to post Share on other sites
Rob_the_Sparky 9 Posted May 31, 2006 A bust igntion amp or cable from dizzy to ignition amp can also stop the injectors but will also stop a spark... Share this post Link to post Share on other sites
